Interfacial grain structure, texture and tensile behavior of multilayer deformation-based additively manufactured Al 6061 alloy

• Published in: Materials characterization 2023-02, Vol.196, p.112646, Article 112646
• Main Authors: Tang, Wenshen, Yang, Xinqi, Tian, Chaobo, Xu, Yongsheng
• Format: Article
• Language: English
• Subjects: Additive friction stir deposition; Aluminum alloy; Friction extrusion additive manufacturing; Grain structure; Tensile behavior; Texture
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2023.112646

Multilayer single-pass 6061 aluminum alloy components were successfully produced by the solid-state friction extrusion additive manufacturing with the aid of a featureless rotating shoulder. The stability of the microstructure and the development of the texture at the interfaces during multilayer deposition, as well as the bonding properties of the final deposits, were carefully evaluated. After undergoing thermal cycling and plastic deformation once, the mean grain size at the interface without defects was 1–2 μm finer than that with kissing bonding defects due to a more extensive recrystallization process, producing a 5.3–20.5% higher proportion of recrystallized grains. After experiencing several thermal cycles and plastic deformation, the grains in the other regions were much smaller than in the area about 30 μm below the interface, where significant grain growth occurred. The grains around the interface without defects were mainly governed by the shear and deformation textures, while the grains around the interface with kissing bonding defects were primarily dominated by deformation and recrystallization textures. The anisotropy of yield strength of the final deposits was determined mainly by the shear textures and the recrystallization textures, whether or not they contained kissing bonding defects. The tensile strength along the build direction of the final deposits without defects could reach 171.4 ± 8.0 MPa, while the value with kissing bonding defects dropped drastically to 121.9 ± 5.4 MPa with elongation at break of only approximately 5.5 ± 1.3%. •Grain growth obviously occurred at defect-free interface after multilayer built.•The interface without defects was governed by shear and recrystallization textures.•The interface with kissing bond showed a much lower plastic deformation capability.